Field of the invention
The present invention relates to a saliva-soluble nicotine containing stimulant unit.
It is a generally recognized fact that active as well as passive smoking of tobacco products such as pipe tobacco, cigars and cigarettes presents serious hazards to public health as well as to the social environment.
It is an equally recognized fact that giving up a smoking habit presents serious problems for a person accustomed to smoking tobacco.
These problems are mainly due to nicotine addiction. It has actually been established that addicted smokers experience an urgent need for tobacco stimulation when the nicotine concentration in the person's blood plasma drops to about 15 ng/ml.
It is further known that various nicotine-containing smokeless stimulants may be used alleviating this urge and thereby assisting smokers to give up their smoking habits without noticable inconvenience.
Prior Art Disclosure
Smokeless nicotine stimulants in form of smokeless tobacco products such as chewing tobacco and snuff have been known for a long time, and various improvements have been suggested.
U.S. Pat. No. 1,376,586 discloses a product comprising fine cut or chewing tobacco in the form of tablets or individual "chews" and having surfaces entirely covered by chicle gum that is impervious to both air and moisture and effective in preventing the evaporation of the tobacco juices.
U.S. Pat. No. 4,545,392 discloses a smokeless tobacco product comprising cut or otherwise comminuted tobacco and 1-35 weight-% of a non-saccharide water-insoluble masticable gum base composition, calculated on the basis of dry tobacco weight, optionally including water-soluble gums such as gum arabic for stabilizing the gum composition, and formulated in the form of pieces of cut or otherwise comminuted tobacco having said masticable gum base composition adhered to the surface as a discontinous coating. According to the citation the individual particles of tobacco should hereby tend to remain dispersed in the mouth.
PCT patent application No. WO 81/02090 discloses a chewing tobacco product in the form of individual portions in which chewing tobacco is coated with or distributed as small particles in a solid or semisolid carrier material. As carrier material, chewing gum is preferred. However, it is further mentioned that starch hydrolysates, e.g. non-sticky products used in the production of "gum drops", may be used as carrier material, although such use is not illustrated by way of examples. Further, the carrier material may contain additives such as flavours, sweeteners, and dried water-soluble extracts of natural product such as coffee or tee extracts.
Nicotine containing sprays or aerosols for oral use are known e.g. from DE-OS 32 41 437 and GB-PS 15 28 391.
Nicotine administration by means of a spray or an aerosol does, however, only provide a short term effect.
A nicotine containing preparation for nasal use is known from DE-OS 34 01 763. However, nasal use is rather unpleasant, since the nose mucous is more sensitive than the mouth mucous. Furthermore this administration too provides only a short term effect. Nasal administration must therefore also be considered less appropriate.
DE-OS 34 38 284 discloses a deposit plaster giving off nicotine by which, however, only a very slow and rather uncontrolled absorption of nicotine is obtained. Further the desirable sudden increase of the nicotine concentration in users' blood plasma and the accompanying physiological experience corresponding to that of the first puffs by smoking a cigarette cannot be achieved by use of a deposit plaster.
A chewable smoking substitute composition in the form of a nicotine containing chewing gum is disclosed in U.S. Pat No. 3,901,248. This composition comprises about 15 to about 80 percent gum base and a nicotine cation exchange resin complex dispersed in the base. The cation exchange resin complex constitutes up to about 10% of the chewing gum composition and affords a nicotine release, when chewed, of approximately that available when smoking a conventional cigarette.
Other improved chewable smoking substitute compositions which are relatively non-irritating to the throat are disclosed in U.S. Pat. No. 3,845,217. These improved compositions comprise about 15 to 80 weight percent gum base, nicotine, and at least one solid physiologically acceptable water soluble buffering agent capable upon chewing of maintaining the pH of the saliva above the normal physiological pH of the saliva, i.e. about 7.4.
The nicotine may be present in a form selected from the group consisting of nicotine free base, a water soluble physiologically acceptable salt thereof, nicotine sorbed on a physiologically acceptable adsorbent, and nicotine in the form of a complex with an insoluble cation-exchanger.
The amount of nicotine present calculated as the free base is from 1 to 10, preferably from about 1 to about 3 mg per chewing gum unit.
In order to obtain a controlled, not too rapid release of nicotine it is preferred to incorporate nicotine as a complex with an insoluble cation-exchanger.
Other chewable smoking substitute compositions of the chewing gum type are disclosed in FR patent application, publ. number 2 608 156. These compositions contain nicotine incorporated in particles which are provided with a surface layer of a water soluble material which allegedly should lead to a controlled, not too rapid release of nicotine.
Generally, smokeless tobacco products based on cut tobacco and carrier materials, e.g. chewing tobacco, communited tobacco distributed in water-soluble gum bases (chewing gums), or starch hydrolysates (gum drops), according to the prior art provide residues of tobacco and/or carriers which are insoluble or difficult to dissolve in the saliva.
Besides that the disposal of these residues may be unpleasant and socially unacceptable, the amounts of ingredients from cut tobacco at the levels required to obtain a nicotine stimulation are high and cause pain in the stomach.
An undesirable sudden release of ingredients e.g. nicotine and flavours may occur by using smokeless tobacco products having a brittle or crystalline type texture when these products are crunched. Hereby large fresh areas of the product may be exposed and the user may receive a large concentrations of the ingredients and consequently experience undesirable variations in the expected physiological effects of the stimulation.
Similar uncontrolled releases of nicotine can occur with nicotine-containing chewing gums when kneaded during mastication.